<!--
@BLINK-ALLOW:live*
@BLINK-ALLOW:container*
@WIN-ALLOW:n_relations*
@MAC-ALLOW:AXSubrole=AXApplicationAlert
-->
<!DOCTYPE html>
<form>
  <label for="in1">Pet name:</label><input id="in1" required>
</form>
<script>
  const in1 = document.querySelector('input');
  in1.setCustomValidity('Please enter pet name');
  in1.reportValidity();
</script>
